Conventionally, a work transport system has been known where, after stopping above a predetermined processing station, a winding drum arranged on the overhead travelling carriage is suitably rotated in both directions and by winding the wire onto the winding drum or feeding out the wire from the winding drum, a chuck device that grips the work moves vertically and stacks work gripped in the chuck device at the processing station or retrieves work from the processing station by gripping the work in the chuck device.
On conventional work transport systems, when batch processing is performed by grouping a plurality of works at a predetermined processing station, a predetermined quantity of work is stacked at the processing station or on the floor near the processing station or a table placed on the floor or the like using the overhead travelling carriage, and thereafter, a predetermined quantity of work is supplied to the processing station using the overhead travelling carriage once again. As conventional work transport systems stack work at the processing station or on the floor near the processing station or on a table placed on the floor or the like in this way, the processing station and floor area must be enlarged.
Furthermore, as the work is stacked at the processing station or on the floor near the processing station or a table placed on the floor or the like, the distance for vertical movement of the chuck device that grips the work increases and as a result, the stacking time of the work increases and the operating efficiency of the overhead travelling carriage decreases.